Method and apparatus for the manufacture of thin walled articles

ABSTRACT

MEASURED QUANTITIES OF METAL POWDER ARE DEPOSITED IN A FEMALE MOLD AND A MALE DIE IS MOVED INTO THE MOLD TO FORM THE METAL POWDER INTO A DESIRED ARTICLE CONFIGURATION. THE FEMALE MOLD AND THE MALE DIE ARE RELATIVELY   ROTATED AND THE FEMALE MOLD IS VIBRATED DURING THE FORMING OPERATION IN ORDER TO EVENLY DISTRIBUTE THE METAL POWDER TO FORM AN ARTICLE HAVING UNIFORM THIN WALLS.

March 2, 1971 J. R. HAKA'LA 3,566,44

METHOD AND APPARATUS FOR THE MANUFACTURE OF THIN WALLED ARTICLES Filed Dec. 22, 1967 PRESSURIIZED AIR SOURCE 22 as I Is I2 ,v JOHN R. HAKALA ATTORNEY United States Patent 3,566,442 METHOD AND APPARATUS FOR THE MAN U- FACTURE 0F THIN WALLED ARTICLES John R. Hakala, Fort Worth, Tex., assignor to Harrison Jet Guns, Inc., Houston, Tex. Filed Dec. 22, 1967, Ser. No. 692,799 Int. Cl. B301) 3/04, 11/00 US. Cl. 18-16 3 Claims ABSTRACT OF THE DISCLOSURE Measured quantities of metal powder are deposited in a female mold and a male die is moved into the mold to form the metal powder into a desired article configuration. The female mold and the male die are relatively rotated and the female mold is vibrated during the forming operation in order to evenly distribute the metal powder to form an article having uniform thin walls.

SUMMARY OF THE INVENTION This invention relates to the formation of thin walled articles, and more particularly to the apparatus for forming thin walled articles from metal powder.

THE PRIOR ART In the perforating of well tubing by the detonation of explosives, it is common practice to utilize a conical, thin walled liner to support the powdered explosive in a shaped charge configuration. These thin walled liners have heretofore been formed by pouring metal powder into -a female mold and moving a male die into the mold while relatively rotating the mold and the die. The powder is evenly distributed by the rotation and is compressed into the desired conical shape by penetration of the die into the mold. The liner is then sintered to form the final article. A description and disclosure of this method of liner manufacture is contained in US. Pat. 3,034,178, issued May 15, 1962.

However, it has been found that conical, thin walled liners having opening diameters slightly more than one inch often are not satisfactorily formed with this method of manufacture. Such larger liners formed by this prior method are often not perfectly uniform in thickness and are not of sufiicient consistency to provide satisfactory penetration when used to perforate well tubing. Further, this previous method of the manufacture of conical liners has required subsequent sintering of the formed liners, thereby increasing the required time and expense of manufacture.

SUMMARY In accordance with the present invention, relatively large conical, thin walled liners are formed by delivering an amount of metal powder into a mold and inserting a die into the mold. The mold and die are relatively rotated to evenly distribute the metal powder and vibration is imparted to the mold. The metal powder is thus compressed into the desired linear configuration without the requirement of an additional step of sintering or the like.

THE DRAWINGS For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view of a finished conical, thin walled liner manufactured in accordance with the invention;

FIG. 2 is a perspective view of the apparatus for forming the liner shown in FIG. 1; and

3,566,442 Patented Mar. 2, 1971 THE PREFERRED EMBODIMENT Referring to FIG. 1, a conical, thin walled liner which has been formed by the present method is designated generally by the numeral 10. Liner 10 has an opening with a diameter greater than one and one-fourth inch, and may have an opening diameter ranging from one and one-half inch to up to four inches. The present method assures that the linear 10 has uniform thin walls throughout the length thereof, and that the liner is frangible by an explosion while having sufiicient strength to securely maintain explosive powder in the desired shaped charge configuration prior to the explosion.

FIGS. 2 and 3 illustrate a system for forming the liner .10. A female mold 12 is supported within a chamber in a barrel 14. An upper chamber in the female mold 12 has a conical configuration for receiving a cone-shaped end 16 of a male die member 18. A platen member 20 is vertically movable in order to contact the top of the male die 18 to exert downward pressure thereon.

An important aspect of the invention is the provision of a vibrator 22 mounted on a collar 24 which comprises a pair of split clamps held in place by a fastener 26. Vibrator 22 may comprise any suitable mechanism for providing vibration of suflicient strength and frequency to enable thin walled liners to be formed according to the invention. A vibrator found to work well in practice is a Martin DD size 16 Vibrolator which is operated by pressurized air supplied through a hose 28 from a suitable air source 30. In operation of the invention utilizing the Martin Vibrolator, air pressures of between 40 to p.s.i. have provided excellent results.

The barrel 14 is seated in a counterbore 32 formed in an upper plate 34. Four tie down clamps 36 are symmetrically spaced about the periphery of the barrel 14 and bear upon a lower annular shoulder 38 -of the barrel 14. Screws 40 are threadedly received in holes in the plate 34 in order to tightly secure the barrel 14 on the plate 34.

A bottom plate 42 is attached to the upper plate 34 by screws 44 and pins 46. The top end of a drive and ejector shaft 48 extends into the end of the female mold 12, with the lower end of the shaft 48 extending below the bottom plate 42. Shaft 48 is movable vertically by a suitable actuator in order to eject the mold 12 from the barrel 14. Additionally, the shaft 48 is rotated by a gear 50 which has a square central opening keyed to the square cross section of the shaft 48. Gear 50 is rotated by a worm gear 52 which is journaled at one end in bearings (not shown) located in the bearing cover 54. The worm gear 52 is rotated by an air motor 56 which is operated by pressurized air fed through a hose 58 from the air source '30.

In operation of the system, a predetermined amount of metal powder is deposited in the cone-shaped chamber formed in the top of the female mold 12. The cone-shaped end 16 of the male die 18 is placed in the corresponding cone-shaped chamber of the female mold 12, as shown in the drawings. The air source 30 is actuated to supply air through the hose 58 to the air motor 56, thereby rotating the worm gear 52 and the gear 50 to cause rotation of the shaft 48 and the female mold 12. The rotation of the female mold 12 causes the metal powder to be evenly distributed between the opposing faces of the female mold 12 and the male die 18.

The platen 20 is then actuated to start its downward vertical movement, and the pressurized air source 30 is actuated to supply air through the hose 28 to energize the vibrator 22. As the platen 20 bears upon the top of the male die 18, relative rotation occurs between the female mold 12 and the male die 18. At the same time, the barrel 14 and the female mold 12 are vibrated at a suitable frequency in order that the metal powder is evenly distributed and compacted in the desired shape. When sufficient pressure has been placed upon the metal powder, the air motor 56 will be stalled and rotation of the female mold 12 will be stopped. The conical, thin walled article is then finished, and no further finishing steps are required. Platen is moved upwardly and the vibration from the vibrator 22 is terminated. The male die 18 is removed, and the ejector shaft 48 is moved up wardly to lift the completed liner 10 and the female mold 12 from the barrel 14. The liner 10 is then removed from the female mold 12.

Whereas the present invention has been described with respect to a specific embodiment thereof, it is to be understood that various modifications and changes will be suggested to one skilled in the art, and it is intended to cover such changes and modifications in the appended claims.

What is claimed is:

1. Apparatus for forming thin walled articles from metal powder comprising:

a female mold for receiving measured quantities of a metal powder supported within a chamber of a supporting barrel,

a male die for being received within said female mold to compress the metal powder therein into the desired thin walled article configuration,

a platen movable with respect to said male die for supplying pressure thereto for compression of the metal powder within the female mold,

motor means mounted to the supporting barrel for imparting generally horizontal vibratory motion to said female mold during the forming operation,

a drive and ejector shaft engaging said female mold, said shaft mounted for vertical movement to eject said female mold from the chamber of the supporting barrel, and

means for imparting rotating motion to said drive and ejector shaft to thereby cause rotation between said female mold and said male die.

2. Apparatus for forming thin walled articles as set forth in claim 1 wherein said means for imparting rotating motion to said drive and ejector shaft includes a motor operated by pressurized air, the output of said motor being overcome to terminate rotation of said female mold when a predetermined pressure is exerted by said platen on said male die.

3. Apparatus for forming thin walled articles from metal powder comprising:

a female mold for receiving measured quantities of a metal powder supported within a chamber in a supporting barrel,

a male die for being received within said female mold to compress the metal powder therein into the desired thin walled article configuration,

a platen movable with respect to said male die for supplying pressure thereto for compression of the metal powder within the female mold,

a collar clamped to the supporting barrel of said female mold,

motor means mounted to said collar for imparting generally horizontal vibratory motions to said female mold during the forming operation,

a drive and ejector shaft engaging said female mold, said shaft mounted for vertical movement to eject said female mold from the supporting barrel, and

means for causing rotation of said female moldwithin the chamber of the supporting barrel and relative to said male die to evenly distribute said metal powder.

' References Cited UNITED STATES PATENTS 2,767,438 10/ 1956 Pingel 18-16 3,149,374 9/1964 Wagner 1816 3,189,942 6/1965 Rapprich et a1. 1816 2,398,227 4/1946 Hubbert 1816.5 2,549,642 4/1951 Seelig 25-41X 2,798,278 7/1957 Johnson 25-4l 3,030,668 4/ 1962 Taylor.

3,034,178 5/1962 Cartier et a1. 18-l6.5X 3,129,463 4/1964 Gill et al 25--41X 3,423,794 1/ 1969 Wilson 18-16.5

J. HOWARD FLINT, JR., Primary Examiner US. Cl. X.R. 185, 42; 25-41 

